Equipment repair management and execution

ABSTRACT

In some examples, a computer system may receive historical repair data and may extract features from the historical repair data for use as training data. The computer system may determine, from the historical repair data, a repair hierarchy including a plurality of repair levels which includes repair actions as one of the repair levels. Furthermore, the computer system may train the machine learning model, which performs multiple tasks for predicting values of individual levels of the repair hierarchy, by tuning parameters of the machine learning model using the training data.

BACKGROUND

When complex equipment experiences a failure, it may be difficult andtime-consuming to determine the cause of the failure and a correspondingrepair action for returning the equipment to a functioning condition.Furthermore, with aging technicians leaving the workforce in someindustries, there may be a knowledge gap created in which newertechnicians may not have sufficient experience to easily determine acause of a failure and a suitable repair procedure for correcting thefailure.

SUMMARY

Implementations herein include arrangements and techniques for trainingand using a machine learning model to determine repair actions. In someexamples, a computer system may receive historical repair data for firstequipment, and may extract features from the historical repair data forthe first equipment as training data including one or more of: free-textvariables associated with comments related to the first equipment; usageattributes associated with the first equipment; equipment attributesassociated with the first equipment; sensor data associated with thefirst equipment; or event data associated with the first equipment. Thesystem may determine a repair hierarchy including a plurality of repairlevels for the equipment. The system may use the training data to traina machine learning model as a multilayer model trained to performmultiple tasks for predicting individual levels of the repair hierarchy.The system may receive a repair request associated with second equipmentand uses the machine learning model to determine at least one repairaction based on the received repair request.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is set forth with reference to the accompanyingfigures. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears. Theuse of the same reference numbers in different figures indicates similaror identical items or features.

FIG. 1 illustrates an example architecture of a computer system able todetermine and implement repairs according to some implementations.

FIG. 2 includes three example flow diagrams illustrating processes thatmay be executed for model training and application according to someimplementations.

FIG. 3 is a flow diagram illustrating an example process for extractingfeatures from free-text variables according to some implementations.

FIG. 4 is a flow diagram illustrating an example process for extractingfeatures from free-text variables according to some implementations.

FIG. 5 is a flow diagram illustrating an example process for extractingfeatures from equipment attributes according to some implementations.

FIG. 6 is a flow diagram illustrating an example process for extractingfeatures from equipment attributes according to some implementations.

FIG. 7 is a flow diagram illustrating an example process for extractingfeatures from usage attributes according to some implementations.

FIG. 8 is a flow diagram illustrating an example process for extractingfeatures from sensor data according to some implementations.

FIG. 9 is a flow diagram illustrating an example process for extractingfeatures from sensor data according to some implementations.

FIG. 10A is a flow diagram illustrating an example process forpreliminary extraction of features from event data according to someimplementations.

FIG. 10B is a flow diagram illustrating an example process forpreliminary extraction of features from event data according to someimplementations.

FIG. 11A is a flow diagram illustrating an example process forpreliminary extraction of features from event data according to someimplementations.

FIG. 11B is a flow diagram illustrating an example process forpreliminary extraction of features from event data according to someimplementations.

FIG. 12 is a flow diagram illustrating an example process for importancemodeling of features extracted from event data according to someimplementations.

FIG. 13 is a flow diagram illustrating an example process for importancemodeling of features extracted from event data according to someimplementations.

FIG. 14 is a flow diagram illustrating an example process for importancemodeling of features extracted from event data according to someimplementations.

FIG. 15 is a flow diagram illustrating an example process for importancemodeling of features extracted from event data according to someimplementations.

FIG. 16 is a flow diagram illustrating an example process for modelbuilding according to some implementations.

FIG. 17 is a flow diagram illustrating an example process for modelbuilding according to some implementations.

FIG. 18 is a flow diagram illustrating an example process fordetermining and executing a repair action according to someimplementations.

DETAILED DESCRIPTION

Some implementations herein are directed to techniques and arrangementsfor a system that determines one or more repair actions, such as inresponse to receiving a repair request following an equipment failure.Examples of equipment failures herein may include breakdown events, suchas when the equipment cannot be operated, as well as soft failures, suchas partial operation, inefficient operation, or otherwise abnormaloperation of the equipment or one of its components. The system hereinmay provide a data-driven system that is able to provide instructions tomaintenance personnel for implementing a repair and/or provideinstructions to the equipment to implement repairs on the equipmentdirectly. In some cases, the system may use analytics technology todetermine a repair plan when the equipment is brought in for repair,which may include using a model trained using historical repair data.

As one example, the system may receive as input: (1) data about theequipment and the working environment of the equipment, and (2) naturallanguage complaints or other comments from a user of the equipmentregarding the failure in need of repair. The system may modelmulti-modal data that includes high-dimensional sparse and dense datacomponents. Some examples include a training mechanism for consistentstructured output prediction, and may further include a mechanism tofocus on key aspects of the equipment environment based on receivednatural language comments and other equipment data. Using thesemechanisms and techniques, the system may determine how to recommend acourse of repair actions from historical repair records and dataassociated with these repairs. In some examples, a repair plan may besent as instructions to the location of the equipment, such as to arepairer computing device or to the equipment itself. In other examples,the system itself may execute the repair plan, such as by remotelyinitiating a repair procedure at the equipment, ordering one or moreparts for the repair, assigning labor for executing the repair,scheduling a time for the repair to be performed, or the like.Accordingly, the system herein may implement repairs, reduce the amountof time that equipment is out of service, increase the efficiency of therepair process, and reduce the likelihood of repair mistakes.

In some examples, a computer system may receive input data for theequipment. The system may identify and extract free-form text in theinput data, such as words, phrases, topics, or other free-form text. Thesystem may also extract a plurality of other features from the inputdata. Examples of the plurality of other features may include equipmentattributes, usage data, sensor data, structured text, event data, andthe like. The system may train at least one machine learning model usingthe extracted features. The system may receive a repair requestassociated with the equipment and may use the at least one trainedmachine learning model to determine at least one repair action based onthe received repair request.

The users of the system herein may include, but are not limited to,equipment end-users and/or operators; repair and maintenance personneland management; and decision makers and operation managers. The systemherein may be used as a standalone solution or may be integrated withother existing systems that provide other functionalities formaintenance management and maintenance optimization and performance.

For discussion purposes, some example implementations are described inthe environment of a computer system that determines repair actions andrepair plans for equipment. However, implementations herein are notlimited to the particular examples provided, and may be extended toother types of equipment, other environments of use, other systemarchitectures, other applications, and so forth, as will be apparent tothose of skill in the art in light of the disclosure herein.

FIG. 1 illustrates an example architecture of a computer system 100 ableto determine and implement repairs according to some implementations.The system 100 includes at least one service computing device 102 thatis able to communicate directly or indirectly with one or more datasources 104. For example, each data source 104 may be a storage directlyconnected to the service computing device 102, may be a storageconnected through one or more networks 106, may include anothercomputing device (not shown in FIG. 1 ) that maintains databases orother data structures of data used by the service computing device(s)102, such as through a network connection or direct connection, may be acloud storage location, or other network or local storage location thatthe service computing device 102 accesses to retrieve the stored data,may be any combination of the foregoing, or any of various otherconfigurations, as will be apparent to those of skill in the art havingthe benefit of the disclosure herein. Accordingly, implementationsherein are not limited to any particular storage apparatus or techniquefor storing the data or portions thereof in the data sources 104.

The data source(s) 104 may receive, store, provide, or otherwisemaintain data used by the service computing device(s) 102. Examples ofdata included in the data source(s) 104 include historical repair data108, equipment attributes 109, usage data 110, sensor data 111, eventdata 112, and user comments and/or error messages 113. The historicalrepair data 108 may include data regarding maintenance and other repairsmade to the equipment in the past. The historical repair data 108 mayinclude repair data for all equipment types and repair types.

The equipment attributes 109 may include structured data that encode theattributes of the equipment subject to repair. Examples include, but arenot limited to, the make and model of the equipment, the manufacturingyear, the capacity and ratings of the equipment and its components. Forinstance, for the same symptoms, different types of equipment mightrequire different repair actions. Therefore, the equipment attributes109 may be used by the model building process to determine the correctrepair for each equipment type given the symptoms of the problem. Thisequipment attributes 109 may be treated as categorical variables, andmay be high-dimensional and sparse.

In addition, the usage data 110 may include structured data related tothe usage of the equipment since the start of operation of theequipment, e.g., from when the equipment was first put into service.Examples include age, operating hours, mileage, payloads, and so forth.Usage data may be useful for determining the appropriate repair actionsgiven the symptoms of the problem to be fixed. In some examples, theusage data 110 may be treated as continuous variables, and may be ahigh-dimensional and dense representation.

Furthermore, the sensor data 111 may include time series data collectedfrom one or more sensors, such as before the equipment failed and/or wassent for repair. Each time series may represent the readings of thesensor over time, such as a sample of a signal from the sensor. Eachsensor data reading may be associated with a timestamp that specifiesthe date and time of the reading of the sensor signal. The sensor data111 may be treated as continuous variables, and may be high-dimensionaland a dense representation.

Additionally, the event data 112 may include information about eventscollected from the equipment, such as before the equipment failed and/orwas sent for repair. The events included in the event data 112 mayinclude different types of events, such as maintenance actions, alarms,notifications, or the like. Each of the events included in the eventdata 112 may be associated with a timestamp that specifies the date andtime of the event occurrence; however, in other examples, a timestampmight not be included. Accordingly, the system herein may consider eventinformation with and without timestamps (e.g., sequential dependencies).The event data 112 may be high-dimensional and sparse representations.

The user comments and/or error messages 113 may include natural languagecomplaints or other comments from the equipment user as well as anyerror messages issued by the equipment or other systems in theenvironment of the equipment. These unstructured or semi-structured datamay describe the symptoms of the problem to be fixed (e.g., “loud noisefrom the back of the equipment”, “equipment overheating”, etc.). Usercomments may be received before or during the repair process, and may bereceived in a variety of different formats including but not limited totyped text, handwritten text, voice notes, voicemail, and the like. Theuser comments and/or error messages 113 may be high-dimensional andsparse.

The service computing device 102 may further communicate over the one ormore networks 106 with one or more client computing devices 115, such asone or more repairer computing devices 114 and/or one or more equipmentcomputing devices 116, each of which may include a repair application118. In some examples, the repair application 118 on each of therepairer computing device(s) 114 and/or the equipment computing device116 may include the same application features and functionality, whilein other examples, the repair application 118 may be customized forindividual repair environments in which it is to be used.

In some implementations, the service computing device 102 may includeone or more servers, personal computers, embedded processors, or othertypes of computing devices that may be embodied in any number of ways.For instance, in the case of a server, the programs, other functionalcomponents, and at least a portion of data storage may be implemented onat least one server, such as in a cluster of servers, a server farm ordata center, a cloud-hosted computing service, and so forth, althoughother computer architectures may additionally or alternatively be used.

In the illustrated example, the service computing device 102 includes,or otherwise may have associated therewith, one or more processors 120,one or more communication interfaces 122, and one or morecomputer-readable media 124. Each processor 120 may be a singleprocessing unit or a number of processing units, and may include singleor multiple computing units, or multiple processing cores. Theprocessor(s) 120 may be implemented as one or more central processingunits, microprocessors, microcomputers, microcontrollers, digital signalprocessors, state machines, logic circuitries, and/or any devices thatmanipulate signals based on operational instructions. For instance, theprocessor(s) 120 may be one or more hardware processors and/or logiccircuits of any suitable type specifically programmed or configured toexecute the algorithms and processes described herein. The processor(s)120 may be configured to fetch and execute computer-readableinstructions stored in the computer-readable media 124, which canprogram the processor(s) 120 to perform the functions described herein.

The computer-readable media 124 may include volatile and nonvolatilememory and/or removable and non-removable media implemented in any typeof technology for storage of information such as computer-readableinstructions, data structures, program modules, or other data. Forexample, the computer-readable media 124 may include, but is not limitedto, RAM, ROM, EEPROM, flash memory or other memory technology, opticalstorage, solid state storage, magnetic tape, magnetic disk storage, RAIDstorage systems, object storage systems, storage arrays, networkattached storage, storage area networks, cloud storage, or any othermedium that can be used to store the desired information and that can beaccessed by a computing device. Depending on the configuration of theservice computing device 102, the computer-readable media 124 may be atangible non-transitory medium to the extent that, when mentioned,non-transitory computer-readable media exclude media such as energy,carrier signals, electromagnetic waves, and/or signals per se. In somecases, the computer-readable media 124 may be at the same location asthe service computing device 102, while in other examples, thecomputer-readable media 124 may be partially remote from the servicecomputing device 102.

The computer-readable media 124 may be used to store any number offunctional components that are executable by the processor(s) 120. Inmany implementations, these functional components comprise executableinstructions and/or programs that are executable by the processor(s) 120and that, when executed, specifically program the processor(s) 120 toperform the actions attributed herein to the service computing device102. Functional components stored in the computer-readable media 124 mayinclude a repair management program 126. The repair management program126 may include one or more computer programs, computer-readableinstructions, executable code, or portions thereof that are executableto cause the processor(s) 120 to perform various tasks as describedherein. In the illustrated example, the repair management program 126may include or may access a data preparation program 128, a relevantdata extraction program 130, a feature extraction program 132, a modelbuilding and application program 134, and a repair plan executionprogram 136.

Each of these functional components 128-136 may be an executable moduleof the repair management program 126, or a portion thereof.Alternatively, in other examples, some or all of these functionalcomponents 128-136 may be separately executable stand-alone computerprograms that may be invoked by the repair management program 126.

The data preparation program 128 may configure the one or moreprocessors 120 to prepare received input data by removing noise andtransforming different data types and/or sources to a format that can beuseful for further analysis. The relevant data extraction program 130may configure the one or more processors to extract, for each repairincident (historical or new), one or more subsets of data that containsymptoms of the problem that needs to be repaired. The featureextraction program 132 may configure the one or more processors toextract features from the relevant data associated with the equipmentsubject to repair. The model building and application program 134 mayconfigure the one or more processors to build one or more machinelearning models used for repair determination from the historical repairdata, and may subsequently apply the one or more machine learning modelsto new repair incidents. Furthermore, the repair plan execution program136 may configure the one or more processors to determine and executeone or more repair plans, such as for executing a repair plan, sendingrepair instructions to a repairer computing device, sending repairinstructions to an equipment computing device, or the like.

Additionally, the functional components in the computer-readable media124 may include an operating system (not shown in FIG. 1 ) that maycontrol and manage various functions of the service computing device102. In some cases, the functional components may be stored in a storageportion of the computer-readable media 124, loaded into a local memoryportion of the computer-readable media 124, and executed by the one ormore processors 120. Numerous other software and/or hardwareconfigurations will be apparent to those of skill in the art having thebenefit of the disclosure herein.

In addition, the computer-readable media 124 may store data and datastructures used for performing the functions and services describedherein. For example, the computer-readable media 124 may store one ormore machine learning models 140, and may store, at least temporarily,training data 142 used for training the machine learning models 140, aswell as reports, client data, repair requests, and other informationreceived from the client computing devices 115. In some examples, thecomputer readable media 124 may encompass the data source(s) 104, whilein other examples, the computer readable media 124 may be separate fromthe data source(s) 104.

The one or more machine learning models 140 may be used by one or moreof the functional components, such as the model building and applicationprogram 134 for determining one or more repair solutions in response toinformation received from one or more of the client computing devices115. Examples of the machine learning model(s) 140 may include deeplearning models, such as deep neural networks and recurrent neuralnetworks. For example, a deep neural network is a type of artificialneural network with multiple layers between the input and output layers.The deep neural network finds the correct mathematical manipulation toturn the input into the output, regardless of whether based on a linearrelationship or a non-linear relationship. The deep neural networkpasses through the layers to determine a probability for each output.Each mathematical manipulation as such is considered a layer. In someexamples herein, the deep neural network may have many layers and isable to model complex non-linear relationships.

Furthermore, while a deep learning model is used in some examplesherein, additional examples of other types of machine learning models140 that may be used in some examples herein may include predictivemodels, decision trees, regression models, such as linear regressionmodels, stochastic models, such as Markov models and hidden Markovmodels, and so forth. Accordingly, some implementations herein are notlimited to a particular type of machine learning model.

The service computing device(s) 102 may also include or maintain otherfunctional components and data, which may include programs, drivers,etc., and the data used or generated by the functional components.Further, the service computing device(s) 102 may include many otherlogical, programmatic, and physical components, of which those describedabove are merely examples that are related to the discussion herein.

The communication interface(s) 122 may include one or more interfacesand hardware components for enabling communication with various otherdevices, such as over the one or more networks 106. Thus, thecommunication interfaces 122 may include, or may couple to, one or moreports that provide connection to the network(s) 106 for communicatingwith the data sources 104, the client computing device(s) 115, and/orone or more external computing devices 145. For example, thecommunication interface(s) 122 may enable communication through one ormore of a LAN (local area network), WAN (wide area network), theInternet, cable networks, cellular networks, wireless networks (e.g.,Wi-Fi) and wired networks (e.g., fiber optic, Ethernet, Fibre Channel),direct connections, as well as short-range wireless communications, suchas BLUETOOTH®, and the like, as additionally enumerated below.

Further, the client computing devices 115 and the one or more externalcomputing devices 145 may include configurations and hardware similar tothose discussed above, but with different functional components, such asthe repair application 118, and different data. The client computingdevices 115 may be any type of computing device able to communicate overa network including server computing devices, desktop computing devices,laptop computing devices, tablet computing devices, smart phonecomputing devices, wearable computing devices, embedded computingdevices, such as electronic control units, and so forth.

The one or more networks 106 may include any type of network, includinga LAN, such as an intranet; a WAN, such as the Internet; a wirelessnetwork, such as a cellular network; a local wireless network, such asWi-Fi; short-range wireless communications, such as BLUETOOTH®; a wirednetwork including fiber optics, Ethernet, Fibre Channel, or any othersuch network, a direct wired connection, or any combination thereof.Accordingly, the one or more networks 106 may include both wired and/orwireless communication technologies. Components used for suchcommunications can depend at least in part upon the type of network, theenvironment selected, or both. Protocols for communicating over suchnetworks are well known and will not be discussed herein in detail.Accordingly, the service computing device(s) 102, the client computingdevice(s) 115, the external computing devices 145, and in some examples,the data sources 104, are able to communicate over the one or morenetworks 106 using wired or wireless connections, and combinationsthereof.

In some implementations, the service computing device 102 may receivethe training data 142 from the one or more data sources 104, such as bystreaming or download. For instance, the model building and applicationprogram 134 may obtain the training data 142 from the historical repairdata 108 and may provide the training data to the data preparationprogram 128, the relevant data extraction program 130, and the featureextraction program 132, as discussed additionally below. The modelbuilding and application program 134 may use the training data 142 totrain the one or more machine learning models 140.

Subsequent to the training of the one or more machine learning models140, the repair management program 126 may receive a repair request 150from one of the client computing devices 115 requesting repair for acorresponding equipment 152. Examples of equipment 152 herein mayinclude vehicles, appliances, construction equipment, manufacturingequipment, robots, electronics, or other types of devices, apparatuses,machines, or the like that may be subject to failure and that may besufficiently complex such that the cause of a failure is not readilyapparent to a repairer 154, such as repair personnel, maintenancepersonnel, or the like. Accordingly, implementations herein are notlimited to particular types of equipment.

In response to receiving the repair request 150, the repair managementprogram 126 may invoke the data preparation program 128, the relevantdata extraction program 130, and the feature extraction program 132, asdiscussed additionally below, to prepare and/or extract data from therepair request 150 and determine model inputs from the information inthe repair request 150. The repair management program 126 may furtherinvoke the model building and application program 134 to apply theextracted information to the machine learning model(s) 140 to determineone or more probable repair solutions for the repair request.

When there is a likely repair solution, the repair management program126 may invoke the repair plan execution program 136 to determine andexecute a repair plan 156 based on the likely repair solution. In someexamples, the repair plan 156, or portion thereof, may be sent to theclient computing device 115 that sent the repair request 150. Receipt ofthe repair plan 156 may cause the repair application 118 on the clientcomputing device 115, such as the repairer computing device 114 in thisexample, to present the repair plan 156 on the repairer computing device114 for viewing by a repairer 154, such as on a display associated withthe repairer computing device 114. The repairer 154 may then perform therepair based on instructions included in the repair plan 156.

Alternatively, the repair plan execution program 136 may execute someportion of the repair plan 156, such as by sending a parts order 158 tothe external computing device 145, scheduling a repairer for repairingthe equipment, scheduling a time for the repair to be performed, or thelike. For example, the external computing device 145 may be a web serveror other suitable computing device including an external application 160able to receive the parts order 158 and provide the repair part to arepairer 154 at a repair location, or the like. Further, the repair planexecution program 136 may provide repair instructions 162 to anequipment computing device 116. In some examples, the repairinstructions 162 may cause the equipment 152 itself to perform a repairor otherwise initiate a repair. For example, the repair application 118on the equipment computing device 116 may receive the repairinstructions 162 and may perform one or more operations in accordancewith the repair instructions 162 for performing the repair.Additionally, or alternatively, in some cases, the repair instructions162 may include computer executable instructions that may be executed bythe equipment computing device 116 for performing or otherwiseinitiating the repair. Accordingly, in some examples, the repair planexecution program 136 may initiate remotely a repair operation via theequipment computing device 116 for performing a repair on thecorresponding equipment 152.

Following the repair, the repair application 118 may cause the clientcomputing device 115 associated with a repair to send repair resultinformation 170 to the repair management program 126. In response, therepair management program 126 may store the received result informationas new data 172 in the historical repair data 108. The new data 172 maysubsequently be used as part of the training data 142 for retraining theone or more machine learning models 140, thereby improving the operationof the one or more machine learning models 140. In addition, if therepair was unsuccessful, in some examples, the repair management program126 may apply the result information 170 as a new repair request fordetermining a new or otherwise additional repair plan for the particularpiece of equipment 152.

FIGS. 2-18 are flow diagrams illustrating example processes according tosome implementations. The processes are illustrated as collections ofblocks in logical flow diagrams, which represent a sequence ofoperations, some or all of which may be implemented in hardware,software or a combination thereof. In the context of software, theblocks may represent computer-executable instructions stored on one ormore computer-readable media that, when executed by one or moreprocessors, program the processors to perform the recited operations.Generally, computer-executable instructions include routines, programs,objects, components, data structures and the like that performparticular functions or implement particular data types. The order inwhich the blocks are described should not be construed as a limitation.Any number of the described blocks can be combined in any order and/orin parallel to implement the process, or alternative processes, and notall of the blocks need be executed. For discussion purposes, theprocesses are described with reference to the environments, frameworks,and systems described in the examples herein, although the processes maybe implemented in a wide variety of other environments, frameworks, andsystems.

FIG. 2 includes three example flow diagrams 200 illustrating processesthat may be executed by the repair management program 126 and otherfunctional components discussed above with respect to FIG. 1 using theone or more processors of the service computing device 102. A first flowdiagram 202 illustrates a process for model training, a second flowdiagram 204 illustrates a process for real time repair processing duringa model application stage, and a third flow diagram 206 illustrates aprocess for batch repair processing. The operations for real timeprocessing and batch processing may be similar in many regards, andaccordingly, only differences between the second flow diagram 204 andthe third flow diagram 206 are described below.

As discussed above, initially the system may train one or more machinelearning models using the historical repair data. For example, therepair data may have been received over time and stored in a database,or the like, for various repair incidents performed by repair personnelfor the type or category of equipment for which the machine learningmodel(s) will be used. For example, if the machine learning model(s)will be used to determine repair plans for trucks, historical repairdata for trucks may be accessed for training the machine learningmodel(s). Similarly, if the machine learning model(s) will be used todetermine repair plans for refrigerators, a database of historicalrepair data for refrigerators may be used. In some examples, thehistorical repair data may be for the same brand of equipment and, insome cases, for the same model or model line of the equipment, dependingon the availability of the historical repair data and the amount of thehistorical repair data. For instance, the historical repair data may beobtained from databases maintained by equipment manufacturers, equipmentrepair shops, or the like. Furthermore, in cases in which there is aninsufficient amount of historical repair data for a particular brand ormodel of equipment, historical repair data for other brands and/ormodels of the equipment may be used in some cases depending on thesimilarities of the respective brands, equipment, or the like.

The training data obtained from the historical repair data and/or thedata included in a repair request received from a client computingdevice may include or may be associated with a plurality of differenttypes of data as mentioned above, such as equipment attributes,equipment usage data, equipment sensor data, event data, user commentsand/or error messages, as well as other user failure-related data, arepair history for the equipment and/or the equipment model, and varioustypes of metadata.

The other failure-related data may include other types of data that maycontain more information about the failure to be repaired. Examples ofthis type of data may include images of defective parts, sound filesfrom recording devices or ultrasonic monitoring devices, videos of thedefective equipment or defective parts and so forth. This data may besubmitted to the system before or during the repair process.

The repair history for the equipment may include historical repairincidents that have already been performed on the equipment forrepairing previous failures. Each prior repair incident may have anassociated timestamp that specifies a time at which the prior repair wasperformed, such as a date and time of day. In some examples, the repairhistory may also include attributes that describe different aspects ofthe repair incident, such as a system or subsystem of the equipment thatwas a source of the failure, one or more components that were replacedor repaired, the parts associated with the repair, and the actions thatwere performed for the repair such as replacing, cleaning, inspecting,and so forth.

The metadata may describe additional information about the environmentin which the equipment is operated. The metadata may include but is notlimited to the operating conditions e.g., operating hours, environmentconditions such as location, temperature, humidity, and maintenancerecords such as date, condition of the equipment, operator notes, andthe like. The metadata may appear in structured, semi structured, orunstructured formats.

As mentioned above, the computing device may initially train one or moremachine learning models using the historical repair data. In thisexample, the model training processing 202 for training the machinelearning model(s) begins at 210.

At 210, the computing device may receive equipment and repair data. Forexample, the computing device may receive historical repair dataincluding any of the types of data discussed above such as equipmentattributes, usage data, sensor data, event data, user comments and errormessages, other failure-related data, repair history, and metadata.

At 212, the computing device may invoke the data preparation program toprepare the received data. For example, the data preparation program maybe executed to remove noise from the received data and transform variousdifferent data types into one or more formats that may be used forfurther analysis. For example, for categorical and numerical data (suchas equipment attributes and usage data) and time-series data (such assensor data), the computing device may remove noise and outliers fromthe data and further may impute any missing data.

Noise and outlier removal may include detecting noise and outliers inthe data values or the sensor readings and removing or replacing thesedata values with values calculated based on similar or nearby records orother readings of the same sensor (e.g., using an average or median ofnearest neighbors). Furthermore, the noise removal may include theremoval of noise due to data-entry errors and removal of repair mistakesor ineffective repairs. For example, repairs that did not result insolving the failure may be removed as not being of use for training themachine learning model. As one example, ineffective repairs may bedetected by identifying equipment that was returned for repair with asimilar complaint within a short time following a first repair.Additionally, as discussed below, ineffective repairs may also beidentified explicitly by repairer feedback, and may be subsequentlyremoved from the training data when the model is retrained.

Furthermore, imputation of missing data may include imputing missingvalues by interpolating values of similar or nearby records, or otherreadings of the sensor time series at nearby timestamps. In some cases,the imputation may be conducted using a regression model for theoriginal time series and finding the values of the regression functionat common timestamps, although other techniques will be apparent tothose of skill in the art having the benefit of the disclosure herein.

In addition, the data preparation performed herein may include naturallanguage data preparation of any received natural language data. As anexample, for a user comment, such as a complaint about the equipment,the computing device may initially convert the user comment to a textformat. For instance, if the user comment is available as an image of ahandwritten note, the system may employ an optical character recognition(OCR) algorithm to recognize the text of the user comment.Alternatively, if the user comment is available as a voice note, thecomputing device may employ a speech-to-text algorithm to convert thespeech signal into a natural-language text.

After the text of the user comment is extracted, the extracted text maybe cleaned, such as by removing special characters, removing stop words,normalizing abbreviations, normalizing synonyms, correcting typos, andperforming stemming. For example, special characters (e.g. “;”, “#”,“!”, “@”), may be removed from the input text, and the text may furtherbe tokenized into words (tokens), such as in lower case letters.Furthermore, domain-specific tokens may be normalized to a unifiedformat (e.g., error codes “1234/567” and “1234567” may be normalized toa consistent format, and measurements such as “30 mph” and “30 mph” maybe similarly normalized).

Additionally, stop word removal includes the removal of common wordsthat do not add useful information to the problem description (e.g.,“in”, “a”, “of”, “the”, “is”). This step might utilize a general purposeor domain-specific list of stop-words. Furthermore, normalization ofabbreviations may expand and normalize abbreviations encountered in thetext, such as by changing “cel” to “check engine light”, etc. Inaddition, synonyms may be normalized to a selected term by identifyingand normalizing pairs of synonyms in the domains. Further, textcorrection may include detecting and correcting typos in the text, suchas changing “leek” to “leak” and so forth. Finally, stemming may includeconverting all words to their stem to reduce the lexical variations inthe input text (e.g., “leaked”, “leaking” and “leaks” may all beconverted to the stem “leak”). The aforementioned cleaning steps canalso be applied to other data types that include unstructured text, suchas error messages from computer systems inside the equipment or in theenvironment of the equipment. Additionally, for other data types, suchas images, sound files, or video files, standard data cleaning andpreparation techniques may be applied, as is known in the art.Furthermore, parameter values 213 used by the data preparation programfor preparing the training data may be logged and used subsequently bythe data preparation program when preparing data received with a repairrequest during the model application stage as discussed additionallybelow.

At 214, the computing device may invoke the relevant data extractionprogram to extract relevant data from the prepared data. For example,this operation may include extracting segments of data that are relatedto the repair at hand. Given the time of failure t_(f), the followingdata segments may be extracted:

-   -   (a) Equipment attributes: the computing device may extract all        the attributes of the equipment subject to repair.    -   (b) Usage data: the computing device may extract the usage data        at the time of the failure t_(f). If usage data is not available        at that time, the computing device may extrapolate the latest        usage data to estimate the usage at t_(f).    -   (c) Sensor data: the computing device may extract all sensor        measurements within a first threshold time period T₁ before the        time of failure t_(f).    -   (d) Event data: the computing device may extract all events        within a second threshold time period T₂ before the time of        failure t_(f).    -   (e) User comments and error messages: the computing device may        use all natural-language comments and error messages generated        before the failure, or following the failure during the repair        process.    -   (f) Other failure-related data: the computing device may extract        all other failure-related data files generated before or during        the repair process.    -   (g) Repair history: for training data, the computing device may        extract all the details of prior repair processes (e.g.,        system(s), subsystem(s), component(s), part(s), and repair        action(s) performed), and use these details as the target labels        that are to be learned by the machine learning model.    -   (h) Metadata: for time-varying data, the computing device may        extract only data instances within a third threshold time period        T₃ before the time of failure t_(f). For static data, the        computing device may extract all the attributes related to the        equipment or environment. Furthermore, parameter values 215 used        by the relevant data extraction program for extracting the        training data may be logged and used subsequently by the        relevant data extraction program when extracting data from data        received with a repair request during the model application        stage as discussed additionally below.

At 216, the computing device may invoke the feature extraction programto perform feature extraction from the multi-modal extracted data. Forexample, given the variables that were extracted during the relevantdata extraction operation discussed above, the computing device may usethe variables as input to a deep learning architecture, or the like. Forexample, the deep learning architecture may be configured to integratemulti-modal high-dimensional sparse data as well as dense data. Further,the deep learning architecture may enable importance modeling of eventsto extract relevant event data using user comments, equipmentattributes, and usage data as context information. In addition, the deeplearning architecture herein includes a training mechanism to outputconsistent and accurate structured repairs.

As discussed additionally below, e.g., with respect to FIGS. 3-15 , thefeatures extracted by the computing device may be transformed to featurevectors for the respective repair incident. For training data, thefeatures may be combined into an n×m feature matrix X where the (i,j)-th element represents the value of feature j for repair i, where n isthe number of features and m is the number of repair incidents.Additional details of the feature extraction are discussed below withrespect to FIGS. 3-15 . Furthermore, parameter values 217 used by thefeature extraction program for extracting the features from the trainingdata may be logged and used subsequently by the feature extractionprogram when extracting features from data received with a repairrequest during the model application stage, as discussed additionallybelow.

At 218, the computing device may train the machine learning model(s)using the extracted features. For instance, to recommend repair actions,a machine learning model, such as a deep neural network, recurrentneural network, or other deep learning model may be trained to mapbetween the extracted features and the corresponding repair actions.Other types of machine learning models may additionally, oralternatively, be used, as enumerated elsewhere herein. Training of themachine learning models is discussed additionally below, e.g., withrespect to FIG. 16 .

The trained machine learning model(s) 219 may be configured to outputone or more options for repair actions that may be performed formaintenance or other repair of the equipment along with a probability ofsuccess for each output repair action. The probability of success mayindicate a likelihood that the repair action will successfully repair acurrent failure based on the historical repair data.

At 220, the computing device may learn or otherwise determine repairplans 221 corresponding to the possible repair actions that may beoutput by the trained machine learning model(s) 219. For example, duringthe model training stage, the repair plan execution program may learnfrom the historical repair data, or other sources, the steps taken forimplementing each different repair action that may be determined by themachine learning model. For example, for each repair action that may bea possible outcome of a machine learning model, the repair planexecution program may obtain, e.g., from the extracted data or otherdata sources, the repair steps that are indicted to be used forperforming the repair. Additionally, in some cases, the repair planexecution program may access other data sources, such as an equipmentrepair manual from the equipment manufacturer, to obtain the repairsteps for each possible repair action that may be output by the machinelearning model.

Based on the learned repair steps for each repair action, subsequently,during the model application stage, the repair plan execution programmay, in some examples, execute one or more of the aforementioned stepsusing the learned repair plan. Further, in the case that there aremultiple repair options for a particular failure, the repair planexecution program may select one of the options so that the overallrepair cost may be minimized, and the availability of the equipment maybe maximized. The information about the impact of each repair action(cost and time) may be obtained from external sources or from thehistorical repair data. Accordingly, the repair plan execution programmay configure the service computing device to generate one or morerepair plans 221 based on one or more outputted repair actions output bythe machine learning model(s).

Following training of the machine learning model(s) and followingconfiguration of the repair plan execution program to generate repairplans for the possible repair actions that may be recommended by themachine learning model, the system is ready to execute at the modelapplication stage for either real time processing and as indicated at204 or batch processing as indicated at 206. As mentioned above, theseprocesses are similar. For instance, the real time processing may takeplace as the request for repair is communicated to the service computingdevice, whereas the batch processing may take place after the fact,i.e., at some time (minutes, hours, days) after the repair request hasbeen sent to the service computing device.

At 230, the computing device may receive equipment and repair data, suchas in a repair request from a client computing device, e.g., asdiscussed above with respect to FIG. 1 . Further, the service computingdevice may also receive some equipment and repair data relative to theparticular equipment from the historical repair data or other sources.For example, the equipment attributes, the usage data, the event data,and the repair history may be obtained from the historical repair dataor other sources. Further, the service computing device may receivesensor data and error messages from the equipment itself or from one ormore devices associated with the equipment. In addition, the servicecomputing device may receive user comments and other failure relateddata from the client computing devices or from other devices associatedwith equipment users.

At 232, the computing device may prepare the received data correspondingto the repair request. For example, the computing device may invoke thedata preparation program to remove noise from the received data,normalize the received data, and transform various different data typesinto one or more formats that can be used for further analysis, asdiscussed above at 212. The parameter values 213 used during thetraining stage may be used to prepare the received data. Further, insome cases, the operations 232-240 may be the same for the real timestage 204 and the batch stage 206. However, in other cases theoperations 232-240 executed during the batch repair processing stage 206may differ from the operations 232-240 executed during the real timerepair processing stage 204. For example, although the respectiveoperations 232-240 may perform the same function in each stage 204 or206, the processing steps may be different, such as due to a differencein the nature of the received data 230 to be prepared at 232.

As one example, when determining repairs to recommend for a batch ofinput cases, some implementations may construct all of the features inparallel, pass a feature matrix which contains all the features for allthe input cases, and run a parallel program to multiply this featurematrix with the weights of the model to determine the repair with thehighest probability of success for each case. On the other hand, whenperforming real time data processing, the same operations may beperformed using a single vector of features for the case at hand.Accordingly, the algorithm logic may be the same, but the implementationcode may be different, e.g., for implementing matrix operations onparallel machines during batch mode as compared with using vectormultiplication on a single machine for the real time mode. In somecases, the same code may be used for both batch mode and real time mode,such as by making the real time operation a special case of the batchoperation. In other cases, separate code may be employed for thereal-time case and the batch case. Further, other variations will beapparent to those of skill in the art having the benefit of thedisclosure herein.

At 234, the computing device may extract relevant data from the prepareddata. For example, the computing device may invoke the relevant dataextraction program to extract relevant data as discussed above at 214and as discussed additionally below. The parameter values 215 usedduring the training stage 202 may be used to extract relevant data suchas equipment attributes, usage data, sensor data, event data, usercomments and error messages, other failure-related data, repair history,and metadata.

At 236, the computing device may extract features from the extractedrelevant data. For example, the computing device may invoke the featureextraction program to extract features from the relevant data, asdiscussed above at 216, and as discussed additionally below. Theparameter values 217 used during the training stage may be used toextract features for each variable, such as time-varying variables(e.g., window-level statistics, trends, correlations, and sequentialpatterns), static variable, and free text variables.

At 238, the computing device may determine a repair action andlikelihood of success. For example, the computing device may invoke themodel building and application program to input the extracted featuresinto the trained machine learning model(s) 219. The trained machinelearning model(s) 219 may be executed using the extracted features asinputs to determine, as outputs of the trained machine learningmodel(s), one or more repair actions and a probability of success ofeach of the repair actions.

At 240, the computing device may determine a repair plan based on themodel output. For example, the computing device may invoke the repairplan execution program to determine one or more repair plans based onthe output of the trained machine learning model. As mentioned above,the repair plan execution program may select one or more repair plans221 determined, e.g., from historical repair data or the like, asdescribed above at 220, for implementing the repair action determined bythe trained machine learning model. If there are multiple options forrepair actions, the repair plan execution program may be configured toselect the repair action(s) that are indicated to have the higherprobability of success. Furthermore, if the probability of success forall of the determined repair actions received from the trained machinelearning model(s) are below a threshold probability of success, therepair plan execution program may perform an analysis to determinewhether it is more beneficial to recommend one of the repair actions orsend an indication that the repair action is unknown. The determinationmay be based on whether the overall maintenance cost is minimized, andthe availability of the equipment is maximized. The information aboutthe impact of each repair step (e.g., cost and time) may be obtainedfrom external data sources, domain knowledge, and/or learned fromhistorical repair records.

At 242, the computing device may execute and/or send the repair plan ora portion of the repair plan to a client computing device associatedwith the received repair request. In some examples, the repair planexecution program may execute at least a portion of the repair plan toimplement the repair action determined by the machine learning model.For instance, executing the repair plan may include, but is not limitedto, ordering replacement parts for performing the repair, assigning arepairer to perform the repair, scheduling a repair time for repairingthe equipment, and/or remotely applying a repair to the equipment, suchas in the case of an automatic diagnosis, changing operating conditionsof the equipment, performing a remote firmware upgrade, remotelyadjusting settings of the equipment, remotely initiating cleaning of theequipment, remotely initiating calibration of the equipment, and soforth. Furthermore, in some examples, the repair plan execution programmay send instructions to the repairer computing device for presentationon the repairer computing device. Additionally, in still other examples,the repair plan execution program may send instructions to the equipmentitself, such as to the equipment computing device, which may thenperform or otherwise initiate the repair independently based on thereceived instructions. Numerous other variations will be apparent tothose of skill in the art having the benefit of the disclosure herein.

FIG. 3 is a flow diagram illustrating an example process 300 forextracting features from free-text variables according to someimplementations. For example, the techniques described herein may beapplied during operations 214-216 and/or 234-236 discussed above withrespect to FIG. 2 . In general, a repair may be associated withinformation obtained from multiple data sources. For example, a naturallanguage complaint or other comment from the user may be synonymous to asymptom. The system herein may obtain information about the equipmentthat is to be repaired, because not all repairs may be applicable to allequipment types. Diagnostic information and events are rich informationthat may serve as a guide for determining an appropriate repair.Accordingly, input information may be received in a variety ofmodalities of data that, when combined, may provide an optimal repairfor the equipment. However, the multiple information sources may providedata in different formats. For example, some data may be categorical andsome data may be continuous. The features to be extracted from eachdifferent type of data may be dependent on the data modality.Accordingly, implementations herein are configured to processmulti-modal data to extract appropriate information for determining anoptimal repair plan for the equipment.

As mentioned above, free text may be received by the system such as fromwritten or spoken comments made by an equipment user, a repairer, orfrom various other sources. For free text variables, each word may beencoded into a dictionary and represented numerically. In some examples,the words may be represented by one-hot coded vectors, where the lengthof a vector is equal to the number of unique words in a correspondingcorpus (e.g., the dictionary). This results in free-text comments and/orother free text variables being represented as a sequence of one-hotencoded vectors (e.g., high-dimensional and sparse).

One-hot encoding is a process by which categorical variables areconverted into a format in which a machine learning model is better ableto use the variables for training and/or prediction. For instance,one-hot encoding may be used to perform binarization of categories sothat categorized inputs may be included as a feature for a machinelearning model. As one example, each received input may be categorizedby indicating a “1” if the category is met or a “0” if a category is notmet. One-hot encoding may be represented as a vector in which all theelements of the vector are “0” except one, which has “1” as its value.For example, [0 0 0 1 0 0] may be a one-hot vector in which the inputmatches the fourth category in a six-category vector. One-hot encodingmay result in a high-dimensional sparse matrix. For instance, in thecase of a dictionary with 10,000 words, following one-hot encoding, eachrow of the matrix may have a “1” in one position corresponding to thematching word, and a “0” in the other 9,999 positions.

As illustrated in FIG. 3 , the high-dimensional and sparse free-textvariables may be mapped onto a low-dimensional continuous variable spaceusing a learnable dimension reduction method. In some cases, thelearnable dimension reduction method may be performed using an embeddingmatrix. For instance, the embedding matrix may map a high-dimensionalsparse vector to a low-dimensional dense vector. The result of dimensionreduction may include a sequence of low-dimensional dense vectors.

Because the free text variables may correspond to natural languagesentences, the resulting low-dimensional dense vectors may have asequential dependency on each other. To extract features, a learnablesequential feature extraction method may be applied. One example of asuitable sequential feature extraction method may be the use of LongShort-Term Memory (LSTM) units. Another example of a suitable sequentialfeature extraction technique is Conditional Random Field (CRF)extraction. The feature extraction process may extract features from thefirst vector on the left (representing the first word of the sentence orphrase) to the last vector on the right (representing the last word).For robustness, implementations herein may also extract sequentialfeatures from right to left as well, thus resulting in two featurevectors from each free-text comment.

In addition, the determined feature vectors may be combined or otherwiseaggregated to determine a final feature vector from the free-textcomment and/or free-text variables. As one example, the feature vectorsmay be aggregated by calculating the mean of the two feature vectors.The parameters of the learnable dimension reduction and the sequentialfeature extraction methods (left to right, and right to left) arelearned during the model training process, such as based on optimizationof an error/loss function.

At 302, the service computing device may receive free text variables.For example, the service computing device may receive written or verbalcomplaints or other comments related to the equipment from the user ofthe equipment, the repairer of the equipment, a manager, or otherpersonnel associated with the equipment.

At 304, the service computing device may perform one-hot encoding on thereceived free text variables. For example, the service computing devicemay categorize each word in the received free text according to adictionary, such as by matching each word in the received free text toone of the words in the dictionary in a one-hot encoding matrix.

At 306, the service computing device may perform learnable dimensionreduction on the one-hot encoded free text variables. As mentionedabove, the learnable dimension reduction may be performed using anembedding matrix or the like. For instance, the embedding matrix may mapa high-dimensional sparse vector to a low-dimensional dense vector.Thus, the dimension reduction may produce a plurality of low-dimensionaldense vectors, e.g., one vector for each word in the received free text,and the vectors may have a sequential dependency on each other.

At 308 and 310, the service computing device may perform learnablesequential feature extraction on the plurality of the vectors. Forinstance, the learnable sequential feature extraction may be performedfor each vector 1-N. Thus, at 308, the feature extraction process mayextract a first feature 312 from the first vector on the left(representing the first word of the sentence or phrase) to the secondfeature 314, representing the second word, to the Nth feature 316 on theright (representing the last word). Additionally, at 310, forrobustness, implementations herein may also extract sequential featuresfrom right to left as well, e.g., from 316 to 314 to 312, thus resultingin two feature vectors from each free-text comment.

At 318, the service computing device may aggregate the extractedfeatures by combining the two feature vectors from 308 and 310respectively. As one example, the two feature vectors may be aggregatedby calculating the mean of the two feature vectors.

At 320, the service computing device may output the aggregated extractedfeatures for use with a machine learning model, such as for modeltraining during a model training stage, or for use as an input to themodel during a model application stage.

This example may employ LSTM units for the sequential feature extractionmethod.

At 402, the service computing device may receive free text variables.For example, the service computing device may receive written or verbalcomplaints or other comments related to the equipment from the user ofthe equipment, the repairer of the equipment, a manager, or otherpersonnel associated with the equipment.

At 404, the service computing device may perform one-hot encoding on thereceived free text variables. For example, the service computing devicemay categorize each word in the received free text according to adictionary, such as by matching each word in the received free text toone of the words in the dictionary in a one-hot encoding matrix.

At 406, the service computing device may use an embedding layer toperform dimension reduction on the one-hot encoded free text variables.As mentioned above, the dimension reduction may be performed using anembedding matrix or the like. For instance, the embedding matrix may mapa high-dimensional sparse vector to a low-dimensional dense vector.Thus, the dimension reduction may produce a plurality of low-dimensionaldense vectors, e.g., one vector for each word in the received free text,and the vectors may have a sequential dependency on each other.

At 408 and 410, the service computing device may use LSTM units toperform learnable sequential feature extraction on the plurality of thevectors. For instance, an LSTM unit is applied to each vector 1 to Nwhere a relevant feature is extracted from each vector. Thus, at 408,the feature extraction process may progress from the first vector on theleft (representing the first word of the sentence or phrase), asindicated at 412, to the next vector, (representing the second word), asindicated at 413, to the Nth vector on the right (representing the lastword), as indicated at 414. The same LSTM unit(s) extract(s) featuresfrom each vector, and there can be multiple such LSTM units, e.g., LSTM1.1, LSTM 1.2, . . . , LSTM 1.n, in this example for extracting featuresfrom each vector. As a result, the features extracted from each LSTMunit form a resultant vector. Additionally, at 410, for robustness,implementations herein may also extract sequential features from rightto left as well, as indicated at 415, 416, and 417, using multiple LSTMunits, LSTM 2.1, LSTM 2.2, . . . , LSTM 2.n, ultimately resulting into asecond feature vector. Thus, traversing of LSTM units from left to rightand vice-versa results the generation of two feature vectors from eachfree text comment.

At 418, the service computing device may calculate the mean of the twofeature vectors to combine the two feature vectors.

At 420, the service computing device may output the aggregated extractedfeatures for use with a machine learning model, such as for modeltraining during a model training stage, or for use as an input to themodel during a model application stage.

FIG. 5 is a flow diagram illustrating an example process 500 forextracting features from equipment attributes according to someimplementations. For example, the equipment attributes may becategorical data and may be represented as one-hot coded vectors. Afterconverting each equipment attribute into a one-hot coded vector, someexamples herein may concatenate or otherwise combine all the extractedvectors, thereby forming a high-dimensional and sparse vector. Similarto the free text variables discussed above, some implementations hereinmay employ a learnable dimension reduction process to convert thehigh-dimensional and sparse vectors into low-dimensional and densevector. One example of a suitable learnable dimension reductiontechnique includes use of an embedding matrix.

At 502 through 504, the service computing device may receive 1st throughnth equipment attributes. As mentioned above, the equipment attributesmay be received from various data sources, such as equipmentmanufacturers, historical equipment data, domain knowledge, equipmentusers, or the like.

At 506 through 508, the service computing device may perform one-hotencoding on the received equipment attributes 1 through N. Similar tothe example discussed above for the free text variables, the one-hotencoding may result in a plurality of high-dimensional sparse vectors.

At 510, the service computing device may concatenate the one-hot encodedequipment attribute vectors.

At 512, the service computing device may perform learnable dimensionreduction on the concatenated high-dimensional sparse vectors. As oneexample, an embedding matrix may be used for the dimension reduction ofthe sparse vectors. Principal Component Analysis (PCA) and LatentSemantic Indexing (LSA) are examples of other techniques that can beused for the dimension reduction of the sparse vectors.

At 514, the service computing device may output the extracted equipmentattribute features for use with a machine learning model, such as formodel training during a model training stage, or for use as an input tothe model during a model application stage.

FIG. 6 is a flow diagram illustrating an example process 600 forextracting features from equipment attributes according to someimplementations. In this example, an embedding layer may be used fordimension reduction.

At 602 through 604, the service computing device may receive 1st throughNth equipment attributes. As mentioned above, the equipment attributesmay be received from various data sources, such as equipmentmanufacturers, historical equipment data, domain knowledge, equipmentusers, or the like.

At 606 through 608, the service computing device may perform one-hotencoding on the received equipment attributes 1 through N. Similar tothe example discussed above for the free text variables, the one-hotencoding may result in a plurality of high-dimensional sparse vectors.

At 610, the service computing device may concatenate the one-hot encodedequipment attribute vectors.

At 612, the service computing device may use an embedding layer toperform dimension reduction on the concatenated high-dimensional sparsevectors. As one example, an embedding matrix may be used for thedimension reduction of the sparse vectors.

At 614, the service computing device may output the extracted equipmentattribute features for use with a machine learning model, such as formodel training during a model training stage, or for use as an input tothe model during a model application stage.

FIG. 7 is a flow diagram illustrating an example process 700 forextracting features from usage attributes according to someimplementations.

At 702 through 704, the service computing device may receive usageattributes 1 through N. As mentioned above, the usage attributes may bereceived from the equipment itself, from the historical repair data,from domain knowledge, from the equipment user, from the equipmentrepairer, or the like. The usage attribute variables may be continuousvariables.

At 706 through 708, the service computing device may normalize thereceived usage attributes. As one non-limiting example, normalizing mayinclude normalizing the values of the received usage attributes to,e.g., be within a range from 0 to 1, although numerous other datanormalization techniques will be apparent to those of skill in the arthaving the benefit of the disclosure herein.

At 710 the service computing device may concatenate or otherwise combinethe normalized usage attribute variables to determine a usage attributefeature vector.

At 712, the service computing device may output the extracted usageattribute features.

FIG. 8 is a flow diagram illustrating an example process 800 forextracting features from sensor data according to some implementations.

At 802 through 804, the service computing device may receive sensor datafrom a first sensor through an Nth sensor. As mentioned above, thesensor data may be received from the equipment itself, from a systemassociated with the equipment, from the historical repair data, from theequipment user, from the equipment repairer, or the like. The sensordata may be high frequency or low frequency data, and may be representedas a continuous and dense vector.

At 806 through 808, the service computing device may normalize thereceived sensor data. As one non-limiting example, normalizing mayinclude normalizing the values of the received sensor data to, e.g., arange from 0 to 1, although numerous other data normalization techniqueswill be apparent to those of skill in the art having the benefit of thedisclosure herein.

At 810 through 812, the service computing device may perform learnablefeature extraction on the normalized sensor data. As one example, thefeatures may be extracted using a learnable non-sequential method, suchas LSTM units. The parameters of the learnable non-sequential method arelearned during the training process.

At 814 through 816, the service computing device may flatten theextracted sensor features. For example, flattening the sensor datafeatures may include converting the extracted features for each sensorinto a one-dimensional (1-D) feature vector, e.g., a single featurevector for each sensor.

At 818 the service computing device may concatenate or otherwise combinethe extracted sensor data feature vectors to determine a single sensordata feature vector.

At 820, the service computing device may output the sensor data featurevector for use with a machine learning model, such as for trainingduring a model training stage, or as an input during a model applicationstage.

FIG. 9 is a flow diagram illustrating an example process 900 forextracting features from sensor data according to some implementations.

At 902 through 904, the service computing device may receive sensor datafrom a first sensor through an Nth sensor. As mentioned above, thesensor data may be received from the equipment itself, from a systemassociated with the equipment, from the historical repair data, from theequipment user, from the equipment repairer, or the like. The sensordata may be high frequency or low frequency data, and may be representedas a continuous and dense vector.

At 906 through 908, the service computing device may normalize thereceived sensor data. As one non-limiting example, normalizing mayinclude normalizing the values of the received sensor data to, e.g.,have a value within a range from 0 to 1, although numerous other datanormalization techniques will be apparent to those of skill in the arthaving the benefit of the disclosure herein.

At 910 through 912, the service computing device may perform 1-Dconvolutional feature extraction on the normalized sensor data. As oneexample, the features may be extracted using a learnable method such aswith 1-D convolutional filters. A set of 1-D convolutional filters maytraverse across the time axis for each sensor signal performingconvolution to extract the relevant features. For instance, eachconvolution may extract different relevant features. As a result ofthis, a set of features from the sensor signal is extracted. Theparameters of the learnable method, e.g., the 1-D convolutional filters,are learned during the training process.

At 914 through 916, the service computing device may flatten theextracted sensor features. For example, flattening the sensor datafeatures may include converting the extracted features for each sensorinto a 1-D feature vector, e.g., a single feature vector for eachsensor.

At 918 the service computing device may concatenate or otherwise combinethe extracted sensor data feature vectors to determine a single sensordata feature vector.

At 920, the service computing device may output the sensor data featurevector for use with a machine learning model, such as for trainingduring a model training stage, or as an input during a model applicationstage.

FIG. 10A is a flow diagram illustrating an example process 1000 forpreliminary extraction of features from event data according to someimplementations. The event data may have sequential dependency on eachother in some examples, while in other examples, the event data may beindependent of each other. For instance, some events may be related toeach other, while other events may be entirely independent. The process1000 of FIG. 10A may be employed when there is no sequential dependencybetween events, e.g., the events are independent of each other.

At 1002, the service computing device may receive event variables. Forexample, the event variables may be received from the equipment, from asystem associated with the equipment, from the equipment user, from theequipment repairer, or from various other sources. Each event variablemay be a categorical variable.

At 1004, the service computing device may perform one-hot encoding toencode each event variable as a one-hot-coded vector, where the lengthof the vector is equal to the number of unique events in the datacorpus. Once encoded, for each data point, the event variables mayinclude a sequence of one-hot coded vectors.

At 1006, the service computing device may perform learnable dimensionreduction. For instance, in the example of FIG. 10A, there may be nosequential dependency between the received event variables. When theevent data are independent of each other, it is not necessary to performlearnable sequential feature extraction. During dimension reduction, thehigh-dimensional and sparse one-hot coded vectors are mapped on to alow-dimensional and continuous space using a learnable dimensionreduction method. An example of the learnable dimension reduction methodmay include use of an embedding matrix, the weights of which are learnedduring the model training process. Thus, the result of the dimensionreduction method may be a plurality of low-dimensional dense vectors.Because there is no sequential dependency between the events, theresults of the learnable dimension reduction method may be used directlyas the features.

FIG. 10B is a flow diagram illustrating an example process 1010 forpreliminary extraction of features from event data according to someimplementations. In this example, the event data may have sequentialdependency on each other.

At 1012, the service computing device may receive event variables. Forexample, the event variables may be received from the equipment, from asystem associated with the equipment, from the equipment user, from theequipment repairer, or from various other sources. Each event variablemay be a categorical variable.

At 1014, the service computing device may perform one-hot encoding toencode each event variable as a one-hot-coded vector, where the lengthof the vector is equal to the number of unique events in the datacorpus. Once encoded, for each data point, the event variables are asequence of one-hot encoded vectors.

At 1016, the service computing device may perform learnable dimensionreduction. For instance, the high-dimensional and sparse one-hot codedvectors are mapped on to a low-dimensional and continuous space using alearnable dimension reduction method. An example of the learnabledimension reduction method may include the use of an embedding matrix,the weights of which are learned during the model training process.Thus, the result of the dimension reduction method is a sequence oflow-dimensional dense vectors.

At 1018, the service computing device may perform learnable sequentialfeature extraction. For example, the service computing device mayperform sequential feature extraction in a manner similar to thatdiscussed above with respect to FIG. 3 . Accordingly, when there issequential dependency between the event variables, a sequential featureextraction method may be used to extract features, where the left mostvector corresponding to a first feature 1020 represents the first eventin the sequence, a second vector corresponding to a second feature 1022represents a second event in the sequence, and the right most vectorcorresponding to an Nth feature 1024 represents the latest event in thesequence.

FIG. 11A is a flow diagram illustrating an example process 1100 forpreliminary extraction of features from event data according to someimplementations. The process 1100 of FIG. 11A may be employed when thereis no sequential dependency between events, e.g., the events areindependent of each other.

At 1102, the service computing device may receive event variables. Forexample, the event variables may be received from the equipment, from asystem associated with the equipment, from the equipment user, from theequipment repairer, or from various other sources. Each event variablemay be a categorical variable.

At 1104, the service computing device may perform one-hot encoding toencode each event variable as a one-hot-coded vector, where the lengthof the vector is equal to the number of unique events in the datacorpus. Once encoded, for each data point, the event variables mayinclude a sequence of one-hot coded vectors.

At 1106, the service computing device may use an embedding layer toperform dimension reduction. For instance, as in the case of FIG. 10Adiscussed above, there may be no sequential dependency between thereceived event variables. During dimension reduction, thehigh-dimensional and sparse one-hot coded vectors are mapped on to alow-dimensional and continuous space using an embedding matrix, theweights of which are learned during the model training process. Thus,the result of the dimension reduction method may be a plurality oflow-dimensional dense vectors. Because there is no sequential dependencybetween the events, the results of the dimension reduction may be useddirectly as the features.

FIG. 11B is a flow diagram illustrating an example process 1110 forpreliminary extraction of features from event data according to someimplementations. In this example, the event data may have sequentialdependency on each other.

At 1112, the service computing device may receive event variables. Forexample, the event variables may be received from the equipment, from asystem associated with the equipment, from the equipment user, from theequipment repairer, or from various other sources. Each event variablemay be a categorical variable.

At 1114, the service computing device may perform one-hot encoding toencode each event variable as a one-hot-coded vector, where the lengthof the vector is equal to the number of unique events in the datacorpus. Once encoded, for each data point, the event variables are asequence of one-hot encoded vectors.

At 1116, the service computing device may use an embedding layer toperform dimension reduction. During dimension reduction, thehigh-dimensional and sparse one-hot coded vectors are mapped on to alow-dimensional and continuous space using an embedding matrix, theweights of which are learned during the model training process. Thus,the result of the dimension reduction method may be a plurality oflow-dimensional dense vectors.

At 1118, the service computing device may perform sequential featureextraction using LSTM units. For example, the service computing devicemay perform sequential feature extraction in a manner similar to thatdiscussed above with respect to FIG. 4 . Accordingly, when there issequential dependency between the event variables, a sequential featureextraction method may be used to extract features. For instance, an LSTMunit may be applied to each vector 1 to N where a relevant feature isextracted from each vector. Thus, the feature extraction process mayprogress from the first vector on the left, as indicated at 1120,representing a first event in a sequence, to the next vector, asindicated at 1122, representing the second event in the sequence, to theNth vector on the right, as indicated at 1124, representing the latestevent in the sequence. The same LSTM unit(s) extract(s) features fromeach vector, and there can be multiple such LSTM units, e.g., LSTM 1,LSTM 1, . . . , LSTM n, as illustrated in this example, for extractingfeatures from each vector.

In a series of events, not all events are important with respect to thecomments and equipment information. Thus, based on the comments,equipment information (e.g., attributes, usage) features from onlyimportant events should be considered. A mechanism to model eventimportance is described additionally below.

FIG. 12 is a flow diagram illustrating an example process 1200 forimportance modeling of features extracted from event data according tosome implementations. In this example, there is no sequential dependencybetween the event variables. As mentioned above, not all events areimportant for a particular repair. Consequently, this example models theimportance of each event and weights the relevant events higher.

1202-1206 may correspond to blocks 1002-1006 of FIG. 10A.

At 1208, the service computing device may determine or otherwise receivethe features extracted from free-text comments, equipment attributes,and usage variables as discussed above, e.g., with respect to FIGS. 3-7.

At 1210, the service computing device may concatenate or otherwisecombine the features extracted from the free-text comments, equipmentattributes, and usage variables. This concatenated vector represents acontext vector of prior information.

At 1212, the service computing device may concatenate or otherwisecombine the context vector with the respective feature vector determinedfrom each respective event to generate a plurality of context-eventfeature vectors.

At 1214, the service computing device may process each context-eventfeature vector to assign a respective score. For example, eachcontext-event feature vector may be passed through a nonlinear functionto determine a respective score for the respective context-event featurevector. One example of a suitable nonlinear function may include ahyperbolic tangent (tan h) function. For instance, if the tan h functionis used, then each context-event feature vector is converted into ascore ranging from −1 to 1. Accordingly, the result of the operation at1214 may be a plurality of scores ranging from −1 to 1.

At 1216, the service computing device may map the plurality of scores toa probability distribution using a learnable function to determine animportance of the respective context-event feature vectors. One exampleof a suitable learnable function to map the scores to a probabilitydistribution is a softmax function. The softmax function is ageneralization of the logistic function that reduces a K-dimensionalvector z of arbitrary real values to a K-dimensional vector σ(z) of realvalues, where each entry is normalized to a value between 0 and 1, andall the entries add up to 1. The number of output classes of thefunction may be equal to the number of events in the sequence. Thevalues obtained from the function may correspond to the relativeimportance of each event. Accordingly, in this example, the importancevalues may range between 0 and 1, although various other scoring andweighting techniques will be apparent to those of skill in the arthaving the benefit of the disclosure herein.

At 1218, the service computing device may multiply the respectiveimportance value determined for each context-event feature vector withthe respective event feature vector, thereby generating a plurality ofweighted event feature vectors. Because the importance value ismultiplied with the respective event feature vector forming the weightedevent feature vector, if an event is not important, i.e., importancevalue is 0, then the event feature vector is ultimately reduced to 0 andhence does not contribute any information further down in the neuralnetwork.

At 1220, the importance weighted event feature vectors may be flattenedby converting the weighted feature vectors to 1-D feature vector, e.g.,a single feature vector.

At 1222, the event feature vector is output for use with a machinelearning model, such as for training the model during a training stageor for use as an input during a model application stage.

FIG. 13 is a flow diagram illustrating an example process 1300 forimportance modeling of features extracted from event data according tosome implementations. In this example, there is a sequential dependencybetween the event variables. As mentioned above, not all events areimportant for a particular repair. Consequently, this example models theimportance of each event and weights the relevant events higher.

1302-1307 may correspond to blocks 1012-1018 of FIG. 10B.

At 1308, the service computing device may determine or otherwise receivethe features extracted from free-text comments, equipment attributes,and usage variables as discussed above, e.g., with respect to FIGS. 3-7.

At 1310, the service computing device may concatenate or otherwisecombine the features extracted from the free-text comments, equipmentattributes, and usage variables. This concatenated vector represents acontext vector of prior information.

At 1312, the service computing device may concatenate or otherwisecombine the context vector with the respective feature vector determinedfrom each respective event to generate a plurality of context-eventfeature vectors.

At 1314, the service computing device may process each context-eventfeature vector to assign a respective score. For example, eachcontext-event feature vector may be passed through a nonlinear functionto determine a respective score for the respective context-event featurevector. One example of a suitable nonlinear function may include ahyperbolic tangent (tan h) function. For instance, if the tan h functionis used, then each context-event feature vector is converted into ascore ranging from −1 to 1. Accordingly, the result of the operation at1314 may be a plurality of scores ranging from −1 to 1.

At 1316, the service computing device may map the plurality of scores toa probability distribution using a learnable function to determine animportance of the respective context-event feature vectors. One exampleof a suitable learnable function to map the scores to a probabilitydistribution is a softmax function. The softmax function is ageneralization of the logistic function that reduces a K-dimensionalvector z of arbitrary real values to a K-dimensional vector σ(z) of realvalues, where each entry is normalized to a value between 0 and 1, andall the entries add up to 1. The number of output classes of thefunction may be equal to the number of events in the sequence. Thevalues obtained from the function may correspond to the relativeimportance of each event. Accordingly, in this example, the importancevalues may range between 0 and 1, although various other scoring andweighting techniques will be apparent to those of skill in the arthaving the benefit of the disclosure herein.

At 1318, the service computing device may multiply the respectiveimportance value determined for each context-event feature vector withthe respective event feature vector, thereby generating a plurality ofweighted event feature vectors. Because the importance value ismultiplied with the respective event feature vector forming the weightedevent feature vector, if an event is not important, i.e., importancevalue is 0, then the event feature vector is ultimately reduced to 0 andhence does not contribute any information further down in the neuralnetwork.

At 1320, the importance weighted event feature vectors may be flattenedby converting the weighted feature vectors to 1-D feature vector, e.g.,a single feature vector.

At 1322, the event feature vector is output for use with a machinelearning model, such as for training the model during a training stageor for use as an input during a model application stage.

FIG. 14 is a flow diagram illustrating an example process 1400 forimportance modeling of features extracted from event data according tosome implementations. In this example, there is no sequential dependencybetween the event variables.

1402-1406 may correspond to blocks 1102-1106 of FIG. 11A.

1408-1422 may correspond to blocks 1208-1222 discussed above withrespect to FIG. 12 .

FIG. 15 is a flow diagram illustrating an example process 1500 forimportance modeling of features extracted from event data according tosome implementations. In this example, there is a sequential dependencybetween the event variables.

1502-1507 may correspond to blocks 1112-1118 of FIG. 11B.

1508-1522 may correspond to blocks 1308-1322 discussed above withrespect to FIG. 13 .

The features extracted from the free-text comments, the equipmentattributes, the usage data, the sensor data, and the event data may becombined/concatenated to form an information fusion layer. The combinedinformation may then be passed downstream to multiple fully connectedneural networks. The output of the final fully connected neural networkis one or more repair actions having a highest probability of success.

FIG. 16 is a flow diagram illustrating an example process 1600 for modelbuilding according to some implementations. For example, the modelbuilding and application program may be executed to build one or moredeep learning neural network models that may be configured to outputconsistent and accurate structured repair instructions. In some cases,as discussed below with respect to FIG. 18 , the output may include anindication of a probability of success if the instructed repair isapplied.

In some implementations, the repair instruction models herein may bemodeled as a classification task where each class represents a repair.Each repair may be represented as a hierarchy of systems and finally anaction, thus a repair is a location (represented by a hierarchy ofsystems) and a repair action. The number of classes for variousdifferent repair actions may be very high. Conventionally, suchhierarchical classes have been handled by building hierarchicalclassification models, where the system level class acts as a prior forthe sub-system level class. However, the conventional technique leads totwo issues: (1) the number of models is very high and may be difficultto manageable, and (2) the outputs may be inconsistent because of errorpropagation.

On the other hand, implementations herein may model the repair actiondetermination problem not only as a classification problem, but also asa multi-task classification problem. In this case, each task mayrepresent each level of the repair hierarchy. As an example, supposethat “sub-system level 1”, “sub-system level 2” and “action” are threetasks. The output from the neural network, e.g., the repair instructionmay be represented as a tuple (sub system level 1, sub system level 2, .. . , sub system level n, action). Model training of the neural networksin some examples herein may involve the backpropagation algorithm and anoptimization algorithm, such as the naïve gradient descent or itsvariants like stochastic gradient descent, stochastic gradient descentwith nesterov momentum, Adam optimization algorithm, Adagrad, RMSProp,or the like.

The backpropagation algorithm calculates the gradients with respect toeach learnable variable in the neural network using a loss function.Generally, loss function in the case of a classification technique is across-entropy loss function. In the case of the repair actiondetermination herein, as it is modeled as a multi-task classificationproblem, first the cross-entropy loss of each level in the repairhierarchy is calculated, and finally all the cross-entropy losses areadded to form the joint loss function. The joint function is then usedto calculate the gradients using the backpropagation algorithm. Theoptimization function is used to minimize the joint loss function where,in each iteration, the calculated gradients are used to update theparameters of the network. Thus, in the case of determining a repairaction, the optimization algorithm minimizes the losses at a level ofthe repair hierarchy simultaneously. This leads to a single deeplearning model herein learning or otherwise being trained to performmultiple tasks (in this case predict each level of a repair hierarchy).Further, there is no error propagation from top to bottom in thehierarchy as the losses are independent of each other. Thistraining/model building methodology results in a single model beingcapable of handling a large number of repair classes to determineappropriate repairs.

In the example of FIG. 16 , the process may be executed by the servicecomputing device by execution of the model building and applicationprogram.

At 1602, the service computing device accesses or otherwise receivesfree-text variables. For example, the free-text variables may bereceived from any of the sources discussed above.

At 1604, the service computing device may extract features from thereceived free-text variables, e.g., as discussed above with respect toFIGS. 3-4 .

At 1606, the service computing device accesses or otherwise receivesequipment attributes. For example, the equipment attributes may bereceived from any of the sources discussed above.

At 1608, the service computing device may extract features from thereceived equipment attributes, e.g., as discussed above with respect toFIGS. 5-6 .

At 1610, the service computing device accesses or otherwise receivesusage attributes. For example, the usage attributes may be received fromany of the sources discussed above.

At 1612, the service computing device may extract features from thereceived usage attributes, e.g., as discussed above with respect to FIG.7 .

At 1614, the service computing device accesses or otherwise receivessensor data. For example, the sensor data may be received from any ofthe sources discussed above.

At 1616, the service computing device may extract features from thereceived sensor data, e.g., as discussed above with respect to FIGS. 8-9.

At 1618, the service computing device accesses or otherwise receivesevent data. For example, the event data may be received from any of thesources discussed above.

At 1620, the service computing device may extract features from thereceived event data, e.g., as discussed above with respect to FIGS.10A-15 .

At 1622, the service computing device may form an information fusionlayer by concatenating or otherwise combining the features extractedfrom the free-text comments, the equipment attributes, the usage data,the sensor data, and the event data to form the information fusionlayer. The combined information may then be passed downstream to one ormore fully connected neural networks.

At 1624, the service computing device may apply the combined informationto one or more deep learning neural networks. For example, the combinedinformation may be used to train a deep learning neural network or, inan application stage, the combined information may be used an input tothe deep learning neural network.

At 1626 through 1628, the service computing device may represent eachrepair action within a hierarchy of systems and corresponding repairactions. Accordingly, a repair action may be a location within thehierarchy of systems and the corresponding actions. The hierarchy ofsystems and the corresponding repair actions for a free text variable,equipment attribute, usage attribute, sensor data and event data may beobtained from the historical repair data discussed above, e.g., withrespect to FIG. 1 . As the repair action recommendation is modeled as aclassification problem, the hierarchical levels obtained from historicalrepairs may be the target variables that are used to build the model.For example, Hierarchy Level 1 at 1626 may be represented by a system,whereas the Hierarchy Level N at 1628 may be represented as a specificpart in that system. As an example, suppose that Hierarchy Level 1represents a car engine, while a Hierarchy Level 3 (not shown in FIG. 16) may represent a carburetor of the car engine. The corresponding repairaction may also be part of the hierarchy. An example of a hierarchicalrelationship in repair may be a car engine→carburetor→replace, where thecar engine is hierarchical level 1, the carburetor is hierarchical level2, and “replace” (which is a repair action) is hierarchical level 3. Thehierarchical relationship corresponds to the repair action, e.g.,“replace carburetor within car engine”.

At 1630 through 1632, the service computing device may apply a lossfunction, such as a backpropagation algorithm. For example, thebackpropagation algorithm may be used to calculate the gradients withrespect to each learnable variable in the neural network using a lossfunction. In some example, the loss function may be a cross-entropy lossfunction. In the case of the repair action determination herein, it ismodeled as a multi-task classification problem.

At 1634, the service computing device may apply a combined lossfunction. For example, following calculation of the cross-entropy lossof each level in the repair hierarchy at 1630-1632, the servicecomputing device may add the cross-entropy losses together to form ajoint or otherwise combined loss function. The combined loss functionmay then be used to calculate the gradients using the backpropagationalgorithm. If the combined loss is represented by

and a parameter of the model is represented by x, then the gradient ofthe loss with respect to the model parameter,

$\frac{\partial\mathcal{L}}{\partial x}$is computed. Using the computed gradient, the optimization algorithmupdates the model parameter x, for example, using the update rule

${x = {x - {\alpha\frac{\partial\mathcal{L}}{\partial x}}}},$where α is the learning rate. The update rule varies based on theoptimization algorithm being used. An example of the optimizationalgorithm is Stochastic Gradient and its variants. The combined lossfunction computation, gradient computation, model parameter updatecontinues until convergence on the combined loss where the loss is beingminimized.

At 1636, the service computing device may determine whether thecalculated loss is minimized. If so, the process goes to 1638. If not,the process goes to 1640.

At 1638, if the loss is not yet minimized, the service computing devicemay perform gradient calculation using the backpropagation algorithm.For example, the combined loss function may be used to calculate thegradients using the backpropagation algorithm.

At 1640, the service computing device applies the gradients calculatedin 1640 and updates the model parameters. The process then returns toblocks 1604, 1608, 1612, 1616 and 1620 to apply the updated modelparameters. Accordingly, the process may perform one or moreoptimization iterations to minimize the combined loss function where, ineach iteration, the calculated gradients are used to update theparameters of the neural network.

At 1642, if the loss is minimized, the process ends and the modelparameters are saved. For example, the process 1600 may continue untilconvergence on the combined loss where the loss is minimized.

FIG. 17 is a flow diagram illustrating an example process 1700 for modelbuilding according to some implementations. For example, the modelbuilding and application program may be executed by the servicecomputing device to build a deep learning neural network model that maybe configured to output consistent and accurate structured repairinstructions. In some cases, as discussed below with respect to FIG. 18, the output may include an indication of a probability of success ifthe instructed repair is applied.

In FIG. 17 , blocks 1602-1624 are the same as or similar to blocks1602-1624 described above with respect to FIG. 16 .

At 1702 through 1704, the service computing device may represent eachrepair action within a hierarchy of systems and a corresponding action.Accordingly, a repair action may be a location within the hierarchy ofsystems and the corresponding action. The hierarchy of systems and thecorresponding repair action for a free text variable, equipmentattribute, usage attribute, sensor data and event data may be obtainedfrom the historical repair data. As the repair action recommendation ismodeled as a classification problem, the hierarchical levels obtainedfrom historical repairs may be the target variables that are used tobuild the model. For instance, a hierarchy level target variable maycorrespond to each hierarchy level output 1702-1704. In this example, ahierarchy level 1 target variable 1706, may correspond to hierarchylevel 1 output 1702, a hierarchy level N target variable 1708 maycorrespond to hierarchy level N output, and so forth.

At 1712-1714, the service computing device may determine the crossentropy loss for each hierarchy level output 1702-1704 based on thecorresponding hierarchy level 1 target variable 1706-1708. For example,for each hierarchy level a cross-entropy loss function is computed usingthe output of the model for each hierarchy level and the correspondingtarget variable 1706-1708.

At 1716, using the computed cross entropy loss functions of eachhierarchy level 1-N, the service computing device may calculate thecombined loss function by adding the computed loss functions together todetermine the combined loss. As discussed above, if the combined loss isrepresented by

and a parameter of the model is represented by x, then the gradient ofthe loss with respect to the model parameter,

$\frac{\partial\mathcal{L}}{\partial x}$is computed. Using the computed gradient, the optimization algorithmupdates the model parameter x, for example, using the update rule

${x = {x - {\alpha\frac{\partial\mathcal{L}}{\partial x}}}},$where α is the learning rate. The update rule varies based on theoptimization algorithm being used. An example of the optimizationalgorithm is Stochastic Gradient and its variants. The combined lossfunction computation, gradient computation, model parameter updatecontinues until convergence on the combined loss where the loss is beingminimized.

In FIG. 17 , blocks 1634-1642 are the same as or similar to blocks1634-1642 described above with respect to FIG. 16 .

FIG. 18 is a flow diagram illustrating an example process 1800 fordetermining and executing a repair action according to someimplementations. In some examples, the process 1800 may be performed byone or more processors of the service computing device 102 by executingthe repair management program 126 which may invoke one or more of thedata preparation program 128, the relevant data extraction program 130,the feature extraction program 132, the model building and applicationprogram 134, and the repair plan execution program 136 for performingsome of the operations described in the process 1800.

Accordingly, some examples herein include a system for determining arepair action by training and using a deep learning model based onhistorical repairs along with the associated data. The functionsprovided by the system may include, but are not limited to determining acourse of repair actions when the equipment fails; reducing diagnosisand repair time; increasing the availability of the equipment; andreducing the number of repair mistakes. Implementations herein may beused as a standalone solution or may be integrated with existing systemsthat provide other functionalities for maintenance management andoptimization.

At 1802, the computing device may train a deep learning model usinghistorical repair data for equipment as training data. Details of thetraining are discussed above with respect to FIGS. 1-16 .

At 1804, the computing device may receive a repair request associatedwith the equipment. For example, during the model application stagediscussed above with respect to FIG. 2 , the computing device mayreceive a repair request from one of the client computing devicesdiscussed above with respect to FIG. 1 .

At 1806, the computing device may extract features from one or more of:free-text variables associated with user comments related to theequipment; usage attributes associated with the equipment; equipmentattributes associated with the equipment; sensor data associated withthe equipment; or event data associated with the equipment.

At 1810, the computing device may use the extracted features as inputsto the trained deep learning model to determine one or more repairactions.

At 1812, the computing device may determine whether a probability ofsuccess of the one or more repair actions is below a thresholdprobability. For instance, in some cases, if the likelihood of successis low, a repair action may not be provided in response to the repairrequest. According, if the probability of success does not exceed thethreshold, the process may go to block 1814; alternatively, if theprobability of success does exceed the threshold the process may go toblock 1816.

At 1814, if the probability of success does not exceed the cost, thecomputing device may send an indication of a “do not know” messageindicating that the repair request did not provide enough informationfor a repair action to be determined.

At 1816, if the probability of success does exceed the cost, thecomputing device may determine a repair plan and or repair instructionsbased on the output of the one or more machine learning models.

At 1818, the computing device may send an instruction to a repairercomputer to instruct the repairer regarding performing a repair actionto the equipment.

At 1820, the computing device may the initiate a remote operation torepair the equipment and/or may begin execution of the repair plan.

At 1822, the computing device may send the repair plan to the repairercomputer to enable the repairer to view the plan and begin repairs.

The example processes described herein are only examples of processesprovided for discussion purposes. Numerous other variations will beapparent to those of skill in the art in light of the disclosure herein.Further, while the disclosure herein sets forth several examples ofsuitable systems, architectures and environments for executing theprocesses, the implementations herein are not limited to the particularexamples shown and discussed. Furthermore, this disclosure providesvarious example implementations, as described and as illustrated in thedrawings. However, this disclosure is not limited to the implementationsdescribed and illustrated herein, but can extend to otherimplementations, as would be known or as would become known to thoseskilled in the art.

Various instructions, processes, and techniques described herein may beconsidered in the general context of computer-executable instructions,such as programs stored on computer-readable media, and executed by theprocessor(s) herein. Generally, programs include routines, modules,objects, components, data structures, executable code, etc., forperforming particular tasks or implementing particular abstract datatypes. These programs, and the like, may be executed as native code ormay be downloaded and executed, such as in a virtual machine or otherjust-in-time compilation execution environment. Typically, thefunctionality of the programs may be combined or distributed as desiredin various implementations. An implementation of these programs andtechniques may be stored on computer storage media or transmitted acrosssome form of communication media.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described. Rather,the specific features and acts are disclosed as example forms ofimplementing the claims.

What is claimed:
 1. A system comprising: one or more processors; and oneor more non-transitory computer-readable media maintaining executableinstructions, which, when executed by the one or more processors,configure the one or more processors to perform operations including:receiving historical repair data; extracting features from thehistorical repair data as training data; determining, from thehistorical repair data, a repair hierarchy including a plurality ofrepair levels which includes one or more repair actions as one of therepair levels; training a single machine learning model for determiningthe one or more repair actions, the single machine learning modeltrained to perform multiple tasks for predicting values for individualrepair levels of the repair hierarchy, the single machine learning modeltrained by tuning parameters of the single machine learning model usingthe training data, wherein the training the single machine learningmodel includes: determining, for each task of the multiple tasks thatcorrespond to each of the individual repair levels of the repairhierarchy, a respective loss within the single machine learning modelfor each individual repair level of the repair hierarchy, wherein therespective loss indicates an error within the single machine learningmodel; combining the respective losses in the single machine learningmodel determined for each of the individual repair levels of the repairhierarchy to determine a joint loss function; and optimizing the jointloss function during training of the single machine learning model toupdate the parameters of the single machine learning model to performpredictions at each of the individual repair levels of the repairhierarchy.
 2. The system as recited in claim 1, wherein the singlemachine learning model is configured to: determine a repair plan basedon the one or more repair actions and a respective probability ofsuccess determined for each repair action of the one or more repairactions; and perform at least one of: sending an order for a part for arepair; sending a communication to assign labor to perform the repair;sending a communication to schedule a repair time for the repair; orremotely initiating a procedure on equipment to be repaired toeffectuate, at least partially, the repair.
 3. The system as recited inclaim 1, wherein: the historical repair data is for equipment, and theplurality of repair levels in the repair hierarchy includes: one or moresystems of the equipment as a first repair level of the repair hierarchyon which the single machine learning model performs a prediction; one ormore subsystems of the one or more systems of the equipment as secondrepair level of the repair hierarchy on which the single machinelearning model performs a prediction; and the one or more repair actionsto perform on the equipment as a third repair level of the repairhierarchy on which the single machine learning model performs aprediction.
 4. The system as recited in claim 1, the operations furthercomprising, during the training of the single machine learning model,employing a backpropagation algorithm to calculate gradients withrespect to each learnable variable in the single machine learning modelusing the joint loss function.
 5. The system as recited in claim 1,wherein optimizing the joint loss function during the training of thesingle machine learning model is conducted by minimizing the joint lossfunction to minimize, concurrently, the respective losses in the singlemachine learning model that correspond to the individual repair levelsof the repair hierarchy during the training of the single machinelearning model.
 6. The system as recited in claim 1, wherein the jointloss function is determined based on a sum of a cross entropy loss ofeach repair level of the repair hierarchy.
 7. A method for building amachine learning model for determining one or more repair actionscorresponding to a repair request, the method comprising: receiving, byone or more processors, historical repair data; extracting features fromthe historical repair data as training data; determining, from thehistorical repair data, a repair hierarchy including a plurality ofrepair levels which includes the one or more repair actions as one ofthe repair levels; and training a single machine learning model as themachine learning model for determining the one or more repair actions,the single machine learning model trained to perform multiple tasks forpredicting values for individual repair levels of the repair hierarchy,the single machine learning model trained by tuning parameters of thesingle machine learning model using the training data, wherein thetraining the single machine learning model includes: determining, foreach task of the multiple tasks that correspond to each of theindividual repair levels of the repair hierarchy, a respective losswithin the single machine learning model for each individual repairlevel of the repair hierarchy, wherein the respective loss indicates anerror within the single machine learning model; combining the respectivelosses in the single machine learning model determined for each of theindividual repair levels of the repair hierarchy to determine a jointloss function; and optimizing the joint loss function during training ofthe single machine learning model to update the parameters of the singlemachine learning model to perform predictions at each of the individualrepair levels of the repair hierarchy.
 8. The method as recited in claim7, wherein the single machine learning model is configured to determinea repair plan based on the one or more repair actions and a respectiveprobability of success determined for each repair action of the one ormore repair actions.
 9. The method as recited in claim 8, wherein thesingle machine learning model is configured to perform at least one of:sending an order for a part for a repair; sending a communication toassign labor to perform the repair; sending a communication to schedulea repair time for the repair; or remotely initiating a procedure onequipment to be repaired to effectuate, at least partially, the repair.10. The method as recited in claim 7, further comprising, during thetraining of the single machine learning model, employing abackpropagation algorithm to calculate gradients with respect to eachlearnable variable in the single machine learning model using the jointloss function.
 11. The method as recited in claim 7, wherein optimizingthe joint loss function during the training of the single machinelearning model is conducted by minimizing the joint loss function tominimize, concurrently, the respective losses in the single machinelearning model that correspond to the individual repair levels of therepair hierarchy during the training of the single machine learningmodel.
 12. The method as recited in claim 7, wherein the joint lossfunction is determined based on a sum of cross entropy loss of eachrepair level of the repair hierarchy.
 13. One or more non-transitorycomputer-readable media storing instructions that, when executed by oneor more processors, program the one or more processors to performoperations comprising: receiving historical repair data; extractingfeatures from the historical repair data as training data; determining,from the historical repair data, a repair hierarchy including aplurality of repair levels which includes one or more repair actions asone of the repair levels; and training a single machine learning modelfor determining the one or more repair actions, the single machinelearning model trained to perform multiple tasks for predicting valuesfor individual repair levels of the repair hierarchy, the single machinelearning model trained by tuning parameters of the single machinelearning model using the training data, wherein the training the singlemachine learning model includes: determining, for each task of themultiple tasks that correspond to each of the individual repair levelsof the repair hierarchy, a respective loss within the single machinelearning model for each individual repair level of the repair hierarchy,wherein the respective loss indicates an error within the single machinelearning model; combining the respective losses in the single machinelearning model determined for each of the individual repair levels ofthe repair hierarchy to determine a joint loss function; and optimizingthe joint loss function during training of the single machine learningmodel to update the parameters of the single machine learning model toperform predictions at each of the individual repair levels of therepair hierarchy.
 14. The one or more non-transitory computer-readablemedia as recited in claim 13, wherein the single machine learning modelis configured to determine a repair plan based on the one or more repairactions and a respective probability of success determined for eachrepair action of the one or more repair actions.
 15. The one or morenon-transitory computer-readable media as recited in claim 14, whereinthe single machine learning model is configured to perform at least oneof: sending an order for a part for a repair; sending a communication toassign labor to perform the repair; sending a communication to schedulea repair time for the repair; or remotely initiating a procedure onequipment to be repaired to effectuate, at least partially, the repair.16. The one or more non-transitory computer-readable media as recited inclaim 13, further comprising, during the training of the single machinelearning model, employing a backpropagation algorithm to calculategradients with respect to each learnable variable in the single machinelearning model using the joint loss function.
 17. The one or morenon-transitory computer-readable media as recited in claim 13, whereinoptimizing the joint loss function during the training of the singlemachine learning model is conducted by minimizing the joint lossfunction to minimize, concurrently, the respective losses in the singlemachine learning model that correspond to the individual repair levelsof the repair hierarchy during the training of the single machinelearning model.
 18. The one or more non-transitory computer-readablemedia as recited in claim 13, wherein the joint loss function isdetermined based on a sum of cross entropy loss of each repair level ofthe repair hierarchy.
 19. The one or more non-transitorycomputer-readable media as recited in claim 13, wherein: the historicalrepair data is for equipment, and the plurality of repair levels in therepair hierarchy includes: one or more systems of the equipment as afirst repair level of the repair hierarchy on which the single machinelearning model performs a prediction; one or more subsystems of the oneor more systems of the equipment as second repair level of the repairhierarchy on which the single machine learning model performs aprediction; and the one or more repair actions to perform on theequipment as a third repair level of the repair hierarchy on which thesingle machine learning model performs a prediction.
 20. The method asrecited in claim 7, wherein: the historical repair data is forequipment, and the plurality of repair levels in the repair hierarchyincludes: one or more systems of the equipment as a first repair levelof the repair hierarchy on which the single machine learning modelperforms a prediction; one or more subsystems of the one or more systemsof the equipment as second repair level of the repair hierarchy on whichthe single machine learning model performs a prediction; and the one ormore repair actions to perform on the equipment as a third repair levelof the repair hierarchy on which the single machine learning modelperforms a prediction.